Expression device for automatic musical instruments.



J. BLOHUT. EXPRESSION DEVICE FOR AUTOMATIG MUSICAL INSTRUMENTS.

APPLICATION FILED NOV. 6, 1912. 1,104,867, Patented July 28,1914

ATTDR NEY5 i unirmeA P ii ernten.

JOSEPH BLOHUT, OF LEIPZIG, GERMANY, ASSIGNOR T0 THE RUDOLPH WURLITZER MANUFACTURING COMPANY, OF NORTH TONAWANDA, NEW YORK, A CORPORA- TION 0F NEW YORK.

EXPRESSION DEVICE FOR AUTOMATIC MUSTCAL INSTRUMENTS.

Specification of Letters Patent.

i Patented Juiy es, mia.

Application led November 6, 1912. Serial No. 729,756. y

To all whom it may concern:

Be it known that I', JOSEPH BLoHU'r, a subject of the Emperor of Austria-Hungary, and resident of Leipzig, Germany, have invented new and useful Improvements in Fxpression Devices for Automatic Musical Tnstruments, of which the following is a specication.` Y

This invention relates to the devices employed in automatic musical instruments to diminish or increase the air tension in the wind chest for expression purposes. Tts object is the improvement of the valve mechanism of the expression and tension regulating devices with a View of minimizing friction between theparts, rendering them more sensitivmand responsive` to variations in the air tension and preventing disturbance of one valve by the movement of the other.

Inthe accompanying drawings: Figure 1 is a longitudinal section ,of the expression device associated with a main bellows. Fig. 2 is an enlarged longitudinal section of the expression and tension regulating valves and their controlling pneumatics. Fig. 3 is a transverse section on line 3 3, Fig. 2. Fig. 4 is a plan view of the expression valve.

Fig. 5 is a fragmentary View similar to Fig.

2, showing a modified construction of the regulating valve. Fig. 6 is a top plan view of the roller employed in said modificatlon.

Similar characters of reference indicate corresponding parts throughout the several ligures.

1 indicates a closed valve-box or case connected by a passage 2 with a wind-trunk 3 from whichthe air is exhausted by a main bellows or equivalent exhaust-device of any suitable construction. The device illustrated in the drawings by way of example comprises the customary reservoir ,Ll and pumps or feeders 5.

- 6 indicates a wind chest or chamber which may itself form part of the main suction chamber of the customary action wind chest, not shown, or connected therewith by a conduit or passage 7. This wind chest is connected with the valve-case by a passage S.

Applied to the passage 2 is an expressionvalve 9, preferably a slide-valve, arranged within the case 1 and resting on the bottom thereof. This valve may be guided by a longitudinal rod 10 projecting from itsrear end and passing through an eye 11 secured to the bottom of said case, or by anyother suitable means. This expression valve may be actuated manually or automatically, as desired. `When it is to be operated automatically, it may be 'connected by a rod 12 with the movable member of an expression pneumatic 13 of any suitable construction. This pneumatic is in turn controlled by corresponding expression-perforations in the usual music sheet through the medium of appropriate means `operating to deflate said pneumatic to a greater or less degree to produce corresponding variations in the air tension in the wind-chest, in an obvious manner. The automatic controlling mechanism of the expression pneumatic forms no part of my present invention and is therefore not illustrated.

W'hen the expression valve 9 is to be controlled manually, this may be done by a hand lever 14 connected with the movable member of said pneumatic, or by any other suitable means. The expression valve has one or more ports 15 extending through it and adapted to register more or less fully with the passage 2 to increase or diminish the tension in the wind chest 6 accordingly. This valve port is in turn controlled by a regulating valve 1G governed by a regulating bellows or pneumatic 17 which is in constant communication with the valve-case 1 or the wind chest 6, so as to be under the influence of the air tension in the wind chest. In the construction shown, this pneumatic communicates. with the valve-case 1 by a passage 17a. The regulating valve 1G is constructed and arranged to roll over the back of the expression valve 9, as distinguished from a sliding action. For this purpose the regulating valve'preferably consists of a doubled or U-shaped strip ofexible or elastic material, such for instance, as

spring steel, celluloid or leather. In the conlimb, the latter is caused to roll over the expression valve to a greater or less extent,

lengthening or shortening said lower limb .is reduced accordingly.

and covering or uncovering the valve-ports 15 accordingly. The free rear end of said upper limb is suitably connected with the movable member of the regulating bellows' 17 by a rod 19, so as to be actuated by the same.

To form a tight joint between the rolling regulating valve and the expression valve 9, the latter is preferably faced with a packing strip 20 of leather or other suitable material, this packing having slots or 4ports 21 which` coincide with those of the expression valve. In order to insure free and smooth action of the upper limb of the regulating valve, a suitable guide is arranged above it. This guide preferably consists of one or more longitudinal rods or rails 22 arranged .substantially parallel with the slide Valve 9 and carried by adjusting screws 23 passing through the top of the valve case 1 and engaging cross bars 24 which connect said guide rods. This construction reduces frictional contact between said valve-limb and its guides to a minimum and at the same time tpermits the guides to be'adj usted to the proper position.

The operation of the device is as follows;

Upon actuating the feed pumps 5, the air is.

exhausted from the lwind chest 6 through the passage 8,`valveports 15, passage 2 and wind trunk 3, and at the same time the regulating bellows is exhausted through the passage 17a, the collapse of this pneumatic being lresisted by the usual tenslon spring 25. Assuming the expression .valve to -be set to a predetermined position, say for playing pianissimo, the passage 2 is nearly closed, as shown in the drawings, and the air tension inthe regulating bellows 17, wind chest 6 and the usual striker or motor pneumatics When a comparatively large number of notes are simultaneously played, the air tension in the wind chest diminishes correspondingly, but the spring 25 overcomes the reduced tension and promptly pulls the movable board of the regulating bellows outwardly, opening the regulating valve 16 wider and equalizing the tension to maintain the shade of expression for which theexpression valve isset. When the air tension increases by reason of playing a smaller number of notes,

' the regulating bellows is collapsed more or ret less accordingly, causing the regulating valve to cover the parts of the expression valve to a greater extent and again diminishing the air tension. In this manner, the regulating bellows and valve maintain a praetically uniform air tension under all the various shades of expression for which the expression valve may be set irrespective of whether the instrument plays simultaneously a large or small number of notes. It will be understood that by moving the expression valve toward its open position the loudness of the sound is increased, and vice versa. By employing a rolling regulating valve 16 in conjunction with the sliding expression valve 9, sliding friction between these parts is wholly eliminated, allowing the regulating valve and its controlling bellows to operate freely and practically without restraint, thus rendering these regulating elements more sensitive and responsive to changes in the air tension and obtaining superior expression effects. At the same time, the expression valve is undisturbed by the movement of the regulating valve and can be shifted with little or no resistance from the regulating valve and without materially disturbing the latter.

The construction of the rolling regulating valve may be'modied without departing from the invention. For example, as shown in Figs. 5 and 6, a flexible, non-elastic strip 26 say of leather, may be substituted for the spring-strip 16. In thiscase, the strip is doubled around a roller' 27 journaled in a yoke 28 carried by the front end of the rod 19 of the regulating bellows 17. The lower limb of the strip is fastened to the slide valve 9, as in the first-described construction, while its upper limb is attached to a tension spring 29 fastened to the wall of the valve case 1 and resisting forward movement of said limb. In the operation of this modification, when the regulating bellows is'collapsed, it pushes the roller forward, stretching the spring 29, nnrolling 100 or lengthening the lower limb and covering a greater area of the expression-valve ports; While when said bellows is inflated more or less, said spring reacts and urges the roller in the opposite direction, rolling up or shortening said lower limb and uncovering a greater. area of said ports.

I claim as my invention:

1. In a musical instrument, the combination of a wind chest, a main bellows, tension regulating and expression valves both controlling the passage between the wind chest and the main bellows, said expression valve bein slidably applied to said passage and Iiaving a port, said regulating valve consisting of a doubled flexible strip one member of which is secured to said slide valve and overlies the port thereof, and a. regulating pneumatic communicating with the wind chest and operatively connected with the other member of said strip.

2. In a musical instrument, the combination of a wind chest, a main bellows, tension regulating and expression valves both controlling the passage between the wind chest and the main bellows, said expression valve being slidably applied to said passage and having a' port, said regulating valve consisting of a doubled strip of elastic material, one member of which is secured to 13a `tion of a` Wind chest, a main bellows, tension regulating and expression valves both controllingothepassage between the Wind chest and the main bellows, said expression valve being slidably applied to said passage and havin a port al guide arranged opposite said slie valve and adjustable relatively thereto, said regulating valve con- "sisting of a doubled elastic stri interposed betweenl said guide and said sli e valve, one

limb of said strip coperating with the port 15 of said valve, and actuating means connected' with the other limb of the strap.

Witness my hand this 1st ay of November, 1912'.

JOSEPH BLOHUT.

Witnesses:

C. F. GEYER, E. M. GRAHAM. 

